at the park there is a pool shaped like a circle with a diameter of 22yd a ring shaped path goes around the pool with a width of 6yds. We are going to give a new layer of coating to the path. if one gallon can cover 8yd^2 how many gallons of coating do we need?

Question

saifoo.khan · Answer

pi r^2

saifoo.khan · Answer

find the surface area for that.

anonymous · Answer

idk?

anonymous · Answer

Ah yes, we do need area after all.
Alright, so as saifoo gave it to us, it's pi times radius squared.  So, Kayla, here's the thing:  We've got a bigger circle minus a smaller circle.  What is the bigger circle's radius?

saifoo.khan · Answer

LOl.

anonymous · Answer

Here is a hint:  It's half of the diameter.

saifoo.khan · Answer

Oh Yeas!

anonymous · Answer

11

anonymous · Answer

Great!
So we plug it into our area formula.  What do we get from it?

Reminder:

pi * r squared.

I'll give you two hints to make it easier:
Make pi = 3.14, and r^2 = 121

anonymous · Answer

379.94

saifoo.khan · Answer

RIGHT.

anonymous · Answer

so is that the answer?

anonymous · Answer

??

anonymous · Answer

That's only the area of the bigger circle.  Notice that it's a bigger circle minus a smaller circle.

Let's go to twiddla.  Saifoo, can you explain it to her there while I help brittany?

anonymous · Answer

oh ok so now i need to know the area of the smaller circle....help

anonymous · Answer

Aww... I was hoping saifoo would help us. I'm helping someone else right now, but meet me here and I'll help. http://www.twiddla.com/586693

anonymous · Answer

ok im on there now what do i do

anonymous · Answer

Alright, so you said your area of the path was: 379.94-78.5
=301.44

anonymous · Answer

right

anonymous · Answer

"if one gallon can cover 8yd^2 how many gallons of coating do we need?"
Ignore the yd^2 part.  It's just there to look scary.

If your total area is 301.44, and 8 of these areas can be covered by 1 gallon, how many gallons do you need?

anonymous · Answer

37.68

anonymous · Answer

Hint:  It's like saying: "If I have 300 candies, and want to give an equal amount of candy to 8 kids, how many candies does each get?"

anonymous · Answer

Perfect!

anonymous · Answer

And note that you did most of that yourself!

anonymous · Answer

should i round up or down it has to be a whole number

anonymous · Answer

I would keep it in fraction form, unless they asked you to.  I mean you can have a part of a gallon.  If they asked you for people or something like that, then you'd want to round.  But personally, I'd leave it as 37.68.